The washing, cleaning and caring of one's own body is a basic human need, and modern industry tries continuously to meet these needs of humans in many ways. Of particular importance for daily hygiene is the continuing elimination or at least reduction of body odor and underarm wetness. In the prior art, numerous specific deodorant or antiperspirant body care products are known which have been developed for use in regions of the body having a high density of sweat glands, especially in the armpit area. These are provided in a wide range of administration forms, for example as a powder, in stick form, as an aerosol spray, pump spray, liquid and gel-like roll-on application, cream, gel and as soaked flexible substrates (deodorant wipes).
Cosmetic antiperspirants of the prior art include at least one antiperspirant salt in addition to at least one oil or a fatty substance and an aromatic component or a perfume.
Aluminum halides and aluminum-zirconium halides in the form of chlorides, which are usually basic, are usually used as antiperspirant salt, since they have no skin-irritating effect in contrast to the non-basic aluminum chlorides and aluminum-zirconium chlorides. The disadvantage of the basic aluminum halides and aluminum-zirconium halides, however, lies in the formation of higher molecular weight oligomeric and polymeric aluminum species, which significantly reduce the efficacy of basic aluminum salts and aluminum-zirconium salts in antiperspirants.
For this reason, in the prior art it has been attempted to increase the efficacy of basic aluminum halides and aluminum-zirconium halides by activation, but at the same time maintain good skin compatibility. Documents EP 0308937 A2, EP 0183171 A2, U.S. Pat. No. 4,359,456 A and EP 0191628 A2 thus describe basic aluminum halides and aluminum-zirconium halides, particularly aluminum chlorides, which were obtained by a thermal treatment. The heat-treated activated basic aluminum halides and aluminum-zirconium halides exhibit, in gel permeation chromatography (GPC), a lower percentage of high molecular weight species in comparison to untreated basic aluminum halides and aluminum-zirconium halides and thus an increased efficacy against sweating in antiperspirants.
Furthermore, the efficacy of basic aluminum halides and aluminum-zirconium halides can be increased by incorporating organic acids as complex ligands. Thus, in documents U.S. Pat. Nos. 3,542,919 A, 3,553,316 A, 3,991,176 and WO 2005/092795 A1, methods are disclosed for producing such stabilized aluminum halides and aluminum-zirconium halides which have a higher proportion of short-chain species and are present in activated form.
A disadvantage of the above-mentioned activated basic aluminum halides and aluminum-zirconium halides of the prior art consists in the decrease of the antiperspirant effect with increasing storage time and/or with the use of protic solvents. This is due to the fact that the polymer distribution of the aluminum species is based on a reversible equilibrium, and this equilibrium in protic solvents shifts with increasing time to higher molecular weight aluminum species and therefore to less effective aluminum species.
There is thus a need for cosmetic antiperspirants having no shift in the polymer distribution to long-chain polymers, and thus no significant decrease in the antiperspirant effect, even during long storage periods and/or when using high amounts of protic solvents. Furthermore, the antiperspirants should be inexpensive to produce.
The present invention had the object of providing a cosmetic antiperspirant which avoids or at least mitigates the disadvantages of the prior art, and with which no significant decrease in the activation of antiperspirant aluminum salts occurs during prolonged periods of storage and/or in the presence of protic solvents.
It has now been found, surprisingly, that the use of alkylsulphonic acids or salts thereof in cosmetic products having antiperspirant aluminum salts leads to a significantly increased formation of short-chain aluminum species as well as to an effective stabilization of these short-chain aluminum species even over long periods of storage.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with this background of the invention.